More blue and gold macaw.

[billben74]

This time the edge of a feather in Numount (canada balsam substitute).
All transmitted polarised light. Stacks.

x200, na 0.4 cellophane used as wave retarder.



No retarder



x100 na 0.25 retarder.



No retarder

[Manfred]

Great pictures, I especially like first and third one

[mrsonchus]

Very nice set, I like most the first and fourth.
What's this cellophane-retarder thingy and how can I give it a try old chap - it sounds interesting!

I love your invention and this series is as always nicely done and revealing in more than just a 'technical' realm my friend, to my eyes.

[billben74]

Many thanks Manfred and mrsonchus.

The cellophane retarder thinging is almost just that.

Get your crossed polaroid set up working, with extinction.

Then get some cellophane wrapper, mine is from a box of snowcoat slides. Rest a flat piece of cellophane on the polarising filter that sits on your lamp house. Turn it. The background colour will turn from black to other colours as you rotate the cellophane.
I mainly get yellow but this varies a bit. The forground colours also change, in this instance to the reds/blues you see. You can get fancy versions of this: mica fliters etc when they are called wave retarders as they are (I think) shifting the phase of polarised light.
I would like to find a way to get some different changes in colours, at the mo I'm limited to a shift to yellow shades. But I think I just need to try other transparent polymers.

Easy one to try out...

[zzffnn]

Your yellow shift may be caused by the feathers themselves. Try a crystal slide and more color variety should come up.

I sandwich cellophane between two glass slides to make it flat - I heard that may help with optical quality.

You may also try overlaying two layers of cellophane for a "half wave plate".

[rnabholz]

Very interesting composition!

[billben74]

Many thanks zzffnn.
Good idea with the slides, and also the doubling up. Will definately try. Perhaps a circular piece of glass...this could lead something semi-permanent which would be good.
For this subject, I actually like the yellow. The feather is yellow (well the bit I snipped off and mounted) and the subject is from a blue and yellow (/gold) maccaw so I'm happy with the yellow/blue in the image as this ties in with the name/subject.

Many thanks rnabholz.

[mrsonchus]

Excellent - I'm definitely going to have a dabble with this black-art my friend!

[JimT]

Like the images, with and without the retarder. Another thing to try which I am quite happy with is a piece of a CD jewel case. stiffer than cellophane.

JimT

[billben74]

Many thanks JimT.
Jewel case also sounds good.

[gekko]

Very nice!

[vasselle]

Bonjour
Bravo pour votre travail
Car les photos sont superbes.
Merci pour le partage
Cordialement seb